Safety appliance for elevators.



H. BURRMANN.

SAFETY APPLIANCE FOR ELEVATORS.

APPLICATION FILED SEPT.22. 1913.

1,134,182,a Patented Apr. 6,19151 2 SHEETS-SHEET 1.

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H. BURRMANN.

SAFETY APPLIANCE FOR ELEVATORS.

APPLICATloN FILED sEP.22, 1913.

1,1 34:, 182. Patented Apr. 6,1915,

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1HE NoRRls PEYER FFTCE.

HENRY BURRMANN, 0F DAVENPORT, IOWA.

SAFETY APPLIANCE FOB ELEVATORS.

Specification of Letters Patent.

'Patented Apr. 6, 1915.

Application filed September 22, 1913. Serial No. 791,076.

T0 all whom t may concern Be it known that I, HENRY BURRMANN, a citizenof the United States of America, and resident of Davenport, Scottcounty, Iowa, have invented a certain new and useful Improvement inSafety Appliances for Elevators, of which the following is aspecification.

My invention relates to safety appliances for passenger or freightelevators and has for its object to provide a means to automaticallystop the cage or car from falling due to accidental breakage of thelifting mechanism.

Another object is to utilize the weight of the car to securely suspendit at any point in the elevator shaft where failure of the liftingmechanism might occur, and the providing of means, accessible from theinterior of the car, for releasing it from such suspended position.

These and other objects which may hereinafter appear I attain by the'mechanism illustrated in the accompanying drawings in which- Figure 1is a front elevation of the lower portion of an elevator car with myimproved mechanism suspended from the floor thereof. Fig. 2 is asectional view taken on line A B of Fig. 1. Fig. 3 is a sectional viewtaken on line D C of Fig. 1. Fig. 4 is a vertical cross section taken online E F of Fig. 1. Fig. 5 is a side elevation of a portion of thedevice taken on line Gr H of Fig. 1. Fig. 6 is a horizontal crosssection taken on line J of Fig. 1. Fig. 7 is a plan view partly insection taken on line K L of Fig. 1. Fig. 8 is a sectional detail takenon line M N of Fig. 6. Fig. 9 is a detail in perspective.

Similar reference characters refer to similar parts throughout theseveral views.

rThe elevator car or cage 1 is of the usual form and raised and loweredin an elevator shaft by cables (not shown) in the usual manner. Theparticular type of car or cage and the manner of guiding the same in itstravel up and down the elevator shaft forming no part of my invention,further description of the same is deemed unnecessary. Pendant from theunderside of the iioor of the car, at the end thereof and adjacent tothe wall or shaft are the hangers 2-2 and directly opposite at the otherend of the car and adjacent the other wall of well is a like pair ofhangers 2a 2a. Journaled in the lower or free end of these hangers arethe shafts 3 and 3a. Pinned to these shafts are the combined spur andbevel gears A-a with the spur portions meshing with the racks 5-5 Theseracks run from top to bottom of the elevator shaft or well and aresecured to the walls thereof. Meshing with the bevel portions of gears 1-4a are the bevel gears 6 6a which in turn are pinned to the shaft 7.Shaft 7 is suitably supported in hangers 8-81. The hangers S-Sa aresecured at their upper ends to the underside of the car floor and attheir lower ends to the journals 9--9a which loosely engage the shaftsS-Ba and also form a socket bearing for the ends of the shaft 7 Shaft 7is further supported by the additional hangers 10-'-10a which are alsosecured to the car floor and in alinement with hangers 8-82. Alsosecured to the floor of the car and located between the hangers 10-10and in alinement therewith is a bracket consisting of the downwardlyextending arms 11-11 provided with the outwardly extending feet 11a 11a,through which .it is bolted to the car floor, and terminating in thecircular flanged head 11b. Supported by the cross bars 11C are thebearings 11d, and the bearing 11e is carried by the cross bar 11'i forpurposes that will more fully hereinafter appear.

Extending inwardly from the lower end of hanger 10a toward the verticalcenter of the device and immediately above shaft 7 is the arm 12.Journaled in the outer end of arm 12 at one end and extending into andsupported at the other end by the bearing 11i in bracket 11 is thegovernor spindle 18. Pinned to this spindle immediately above the arm 12is the bevel gear 14 which meshes with the bevel gear 15 which in turnis pinned to shaft 7. Securely pinned to spindle 13 near its upper endis the upper governor head 16. Swingingly connected to this head by thearms 17-17 are the governor balls 18-18, which balls are also jointedlyconnected to the lower governor head 19 by the arms 20-20. Head 19slidingly engages spindle 18. Rods 2Oil are rigidly secured to the fourcorners of head 19, pass loosely through openings in the four corners ofhead 16 and are secured to the bottom of the circular plate 21. Thisplate slidingly engages the upper end portion of the spindle 13 and isprovided with the peripheral flange 22. Thus it is seen that plate 21will rise and fall on spindle 13 in response to the raising and loweringof the governor balls by `centrifugal force.' when revolved at highspeed.`

Loosely suspended on shaft 7 is the large,

heavy, highly tempered U shaped steelV spring 2,3.A The free ends ofthis spring are connected by the chains 24-24 to thek spindle 25,*whichspindle is journaled' in the bearings 11d and extends from the upper endofi bracket 11 to the upper end of spinx `vchains 24 and in alinementwith the head 11b Y are the collars 27 27 to which are hinged'the hookedarms 28-28- "Vhen the springisput under tension; as above described, thehooked ends of these arms engage the upper edge of the flange on head11b through openings 11g and hold the spring in tension after which thehand wheel'26 can be released. Immediately below opening 11g is thelaterally extending lip or apron 11h acting as a support for the hookedarms 28 when not engaging the flange of head 11b and acting as a guideto conduct the hooked end of the arm 28 into the opening -when thespring is put` under tension. It will be observed, as clearly shown inFig. 8 that the vdown turned end of arm 282 is in register with the upturned flange 22 of plate 2l and consequently when this plate is raisedby the action ofthe governor balls, 'itwillforce the hooks up and off ofthe edge of the flange on 11b and permit the spring 23- toimmediatelyexpand to its limit. By providing the floor of the car with a-trap door,the operator can at anytime manipulate the --hand wheel 26 andbringthespring vback and lock itin tension.

Secured to shaft 7 vat each end and adj acent the lbevel gears 6 6a arethe friction 'drums 29-29avAdjacent these ydrums Vthe spur gears 30-30ilare pinned to the shaft. Mesh-ing with these gears are the spur gearsvtb-31a which are loosely mounted Jon the counter-shafts 32-322. Theseshafts are journaledl respectively in hangers 8-10 and `8a l0?. f Thehubs of the upper gearsfl-Sla are extended toward the* vertical centerof the device and pass loosely through openings inthe arms of the spring23atthe intersection with the counter shafts, and are providedwith thecolla-rs Blb and pins 31c Aon'each side of the spring arms, so that whenthe spring expands yor is drawn into tension 'the spur `'gears are movedlongitudinally ofthe shaft with it. The outery end ofthe hub of these,gears is provided 4with the notches 31d forming one .halfof a dentalclutc`h. Adjoining these gears *and friction straps '34%843 drums29729a, but upon. the release of hand -arealso notched forming `theother-half-'of a dental clutch. A Y e When the -elevator car ascends ordescends the Vpinionsfi fnieshingv with the stationary racks 5 revolveshaft 7, which throughft'he Ypinned to the same shaft are the collarsv Ymedium of bevel gears lik-15 yrevolves the governor balls 18. Theweightof theseballs and the ratio off-the gearing by `which they aredriven aresuch that-normal speed of travel of the car isnot sufficient;'tocausethem to lift through centrifugal for-ce, but Y when the normal speed isexceededas would follow from the vdropping of the car through breakingof the supporting cables, .the lgovernor-balls would be thrown outand-up withconsiderable force. In thus Vraising the flanged lip 22 ofplate 21, the lip would contact with the hooked-arm 28,- release it andpermitfspring 23- -to expand asl heretofore explained. This lateralexpansion of the spring-.would slide pinions 231-31 on shaft 32%32a andas these pinions are being constantly -revolved by their engagement with`pinions 30.-30a on shaft 7, a'rota-ting movement would-fbe setup in thecollars 33 33a through the engagement of, the

notched ends of their hubs, but as thesecollars cannot revolve beyondthe' limi-tsof elasticity or slackness inthe friction-straps 34, theSentire weight of the descending car is expended in -Wrappingthe ystraps'about the friction `drums'29, thus preventing further rotation rofshaft Tand arresting the descent of the car. Y A

, By .manipulating 'hand wheel 26,v winding chains 24about the spindle25,j2tlie arms of spring- 23 would be drawn l.inwardly and cause.pinions 321-311@ to slide out of-engagement with the collars 33,permitting the car to again start downwardly, viously explained, thepinions-31-31a which are controlled, in their lateralsliding'engagem'ent'with theV shafts '32 -32a,-by the expansion andcontraction of the-spring 23, would be withdrawn from'their engagementwith thegcollars83-33a, .and as these pinions are free to -revolve onthe shafts 32-32a, they could nolonger vretard the downward movementofthe caras they would no longer functionin grippingthe about thefriction wheel 26, which would? permit the spring for, as prel`clutching 23 to expand and slide the pinions 31--31a into clutchingengagement with the collars 33-33, thereby wrapping the friction strapsSil-34a tightly about the drums 2.9-292, descent of the car would beimmediately arrested.

What I claim is- 1. An automatic stop for elevator cars consisting of ahorizontally extending main shaft supported by said car, stationaryracks vertically disposed adjacent to and independent of said car,gearing connecting said racks and shaft, a pair of horizontally disposedcounter shafts, friction drums secured to said main shaft, frictionstraps carried by said counter shafts, and engaging said drums,automatic means controlled by said main shaft whereby the weight of thecar becomes effective in causing said straps to grip said drums.

2. An automatic safety device for elevator cars consisting of ahorizontal main shaft disposed transversely of and supported by saidcar; vertically disposed toothed racks adjacent to and independent ofsaid car, gearing connecting said racks and shaft, a pair ofhorizontally disposed countershafts, friction drums secured to said mainshaft, friction straps carried by said counter-shafts and engaging saidfriction drums, clutch pinions slidably and revolubly mounted on saidcounter shafts, clutch collars rigidly secured to said counter shaftsand said friction straps, automatic means operated by said main shaftfor throwing said clutch members into engagement.

3. An automatic safety device for elevator cars consisting of ahorizontally disposed main shaft supported by said car, verticallydisposed toothed racks adjacent to and independent of said car, gearingconnecting said racks and shaft, a pair of horizontally disposed countershafts, clutch members mounted on said counter shafts, braking mechanismsupported by said counter-shafts and engaging one of said clutch memberson each counter-shaft, a U shaped spring carried by said main shaft andengaging the other clutch member on each of the counter shafts, springlocking means adapted to hold said clutch members out of engagement,automatic spring releasing means controlled by said main shaft forthrowing said clutch members into engagement.

4. An automatic safety device for elevator cars, in combination, ahorizontally disposed main shaft supported by the car, fixed verticallydisposed toothed racks adjacent to and independent of said car, gearingconnecting said racks and shaft, a pair of horizontally disposed countershafts, clutch members mounted on said counter shafts capable ofengagement with each other, braking mechanism supported by saidcounter-shafts and engaging one of said clutch members on eachcounter-shaft, a spring supported by said main shaft and engaging theother clutch member on each of the counter shafts, manually operatedspring locking means adapted to hold said clutch members out ofengagement, and an automatic spring releasing means controlled by thevelocity of the car for throwing said clutch members into engagement.

5. In an automatic safety device for elevator cars, the combination of ahorizontally disposed main shaft supported by said car, verticallydisposed toothed racks adjacent to and independent of said car, gearingconnecting said shaft and racks, a pair of horizontally disposed countershafts, clutchgearing connecting said main shaft and counter shafts,friction drums secured to said main shaft, friction straps capable ofengagement with said friction drums and secured to said counter shafts,automatic means externally of the car controlled by the velocity of thecar adapted to cause engagement of said clutch gearing to cause saidstraps to grip said drums, and means manually operated from within thecar for releasing said clutch gearing.

Signed by me at Davenport, Iowa, this 19th day of September, 1913.

HENRY BURRMANN.

Witnesses:

HENRY H. YERK, ALBERT FRIEDMANN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

